Bearing lubricating structure



Nov. 15, 1960 L. E. s'rAAK 2,960,371

BEARING LUBRICATING STRUCTURE Original Filed April 18, 1955 BEARINGLUBRICATING STRUCTURE Louis E. Staak, Fort Wayne, Ind., assignor toGeneral Electric Company, a corporation of New York Original applicationApr. 18, 1955, Ser. No. 501,963. Divided and this application June 25,1956, Ser. No. `593,588

2 Claims. (Cl. 30S-132) This application is a division of my applicationSerial No. 501,963, filed April 18, 1955 and assigned to the assignee ofthe present application.

This invention relates to bearings for rotating shafts, and moreparticularly to sleeve bearings of the type which are lubricated bymeans of lubricant absorbent material positioned within the bearinghousing.

It is most desirable that sleeve bearings for rotating shafts be capableof operating as long as possible without the necessity of lubricanthaving to be added. During such operation the bearing should, of coure,be fassured of an adequate supply of lubricant. Consequently, it hasbecome conventional in connection with many types of sleeve bearings toprovide a bearing housing within which there is positioned a mass oflubricant absorbent material. This mass acts in effect as a reservoirfor the lubricant and generally is arranged to touch the shaft at one ormore points so that lubricant is gradually fed to the shaft at thebearing surface. While this construction achieves the desired effect, itis both difficult and expensive to `arrange the lubricant `absorbentmaterial properly within the bearing housing due to the relativeinaccessibility of the space within the housing. This has created highcosts in the manufacturing process and has prevented the fullutilization of the space within the bearing housing because of the`diiiculty involved in completely filling the housing through theopenings provided. It will be seen from the foregoing that it is mostdesirable to provide a sleeve bearing structure with the space withinthe bearing housing entirely filled with lubricant absorbent material.

It is, therefore, an object of this invention to provide an improvedbearing structure incorporating the desirable features set forth above.

Further objects and advantages of this invention will become apparentand the invention will be better understood by reference to thefollowing description and the accompanying drawing, and the features ofnovelty which characterize this invention will be pointed out withparticularity in the claims annexed to and forming a part of thisspecification.

In its broadest aspect, this invention provides a bearing which has asleeve member adapted to support a rotatable shaft. A bearing housing issecured to the sleeve member so as to support it and is formed inradially spaced relation to the sleeve member. An integral mass oflubricant-absorbent foam material having an interconnecting cellularstructure is arranged to fill the space between the housing and thesleeve member.

The lubricant-absorbent material is located within the bearing housingby enclosing the space within the housing, introducing into the space arelative small amount of a material including a blowing agent which canbe made to foam either by heat or agitation or a combination of the two,and causing the material to foam and fill the enclosed space. The termblowing agent is used to denote a composition capable of releasing gasso as to blow a material into a foam consistency.

In the drawing, Figure 1 is a side View, partly broken away and partlyin cross section, of dynamoelectric ma- States arent C 2,960,371Patented Nov. 15, 1960 chine having a shaft supported by the improvedbearing of this invention;

Figure 2 is a view along line 2 2 in Figure 1; and

Figure 3 is a side view of the improved bearing of this invention,partly in cross section, illustrating the improved method of making thebearing.

Referring now to Figures 1 and 2 of the drawing, there is shown adynamoelectric machine, generally indicated at 1, provided with a rotormember 2 preferably made up of a plurality of superimposed thinlaminations of magnetic material. Rotor 2 is secured to a shaft 3 whichis rotatably mounted within a bearing 4 secured in -end shield 5 of thedynamoelectric machine 1. Shaft 3 is provided with a shoulder 6 definingan extended portion 7 which has a relativelysmall diameter. Shaftportion 7 is rotatably supported within an insert 8 of a sleeve member 9which is secured by spokes 10 to the bearing housing portion 11. Housingportion 11 may be formed as part of the end shield 2, and is providedwith an opening 12 through which lubricant may be introduced into thebearing and which is adapted to be closed by a standard pressed-in oilcup member 13. An annular housing member 14 terminates at one end in aflange 15 which is engaged with flange 16 of housing portion 11 so that,in effect, housing portion 11 and member 14 form together the completebearing housing.

A lubricant slinger member 17 is secured on extended shaft portion 7, asshown, so as to be rotatable therewith. Slinger 17 has a relativelypointed peripheral sec` tion 18 from which the lubricant is adapted tobe thrown back into part 19 of integral mass Ztl. This mass is formed ofa foam material having an interconnecting cellular structure, and isarranged to fill the space between the bearing sleeve member 9 and thehousing members 11 and 14. In addition, portion 21 of the materialextends into `an opening 22 in sleeve member 9 so as to form a wick inengagement with the surface of extended shaft portion 7. Mass 20 isadapted to be saturated with a suitable lubricant which is fed to thebearing surface through wick 21. The lubricant is adapted to be returnedto part 19 of mass 20 from the periphery 1'8 of lubricant slinger 17 bycentrifugal force. The fact that mass 2@ lls the interior of the bearinghousing structure permits a large quantity of lubricant to be stored andeliminates wasted space. An annular member 23, provided to precludeleakage of lubricant from the bearing, may be secured by a flange 25 tothe outer end 24 of housing portion 11.

Referring now to Figure 3, a preferred method of making the improvedbearing of Figures 1 and 2 will be described. Before the shaft isinserted within sleeve 8 of bearing 4, a pair of mold parts 26 and 27are respectively placed against ends 28 and 29 of sleeve member 9. Part26 includes a large diameter portion which is arranged securely inengagement with end 24 of the bearing housing, a second portion 31 ofintermediate diameter which abuts against end 28 of sleeve member 9, anda third portion 32 which ts within insert S in the same manner asextended portion 7 of shaft 3. Portion 32 of mold part 26 is preferablyprovided with a recess 33 which is arranged to coincide with opening 22in sleeve member 9.

Part 27 has a main portion 36 with a diameter slightly larger than thatof shaft 3 so that it is relatively snugly in engagement with inner end34 of housing member 14, and a second portion 37 which fits withininsert 8 in the same manner -as extended shaft portion 7. A passageway35 is provided in portion 36 for the insertion of the required materialas will fully be set forth below. While passageway 35 has been shown inmold part 27 for illustrative purposes, it will of course be understoodthat this passageway may be equally effectively provided in lthe othermold part 26 or in any suitable pant of the housing members 11 and l14of the bearing.

With mold parts 26 and 27 in place as shown in Figure 3, ythe materialsare inserted through passageway 35, the chemical reaction required toform the foam is achieved either by the provision of heat or agitationor both, as the case may be, and the mold parts 26 and 27 may then beremoved.

As stated before, a prime feature of the invention is to provide a foamhaving `an interconnecting cellular structure so that it will performthe wicking and feeding functions for the bearing lubricant. A greatvariety of different types of ySuch foams are available. It is,therefore, clear that the inventive concept in this application isdirected Ito a bearing structure filled with a particular type oflubricant-absorbent material, and that the broad invention is not to belimited to a specific material. However, for purposes of illustration,two different means of obtaining entirely different foams (from achemical standpoint) each having a suitable interconnecting cellularstructure will be given:

First.-An epoxy resin, characterized by an epoxide equivalent of between190 and 375, was heated to 110 degrees centigrade. A mixture consistingof two grams of ammonium carbonate, five grams of toluene, and two dropsof sorbitan monolaurate polyoxyalkylene derivative, a wetting agent, wasthen mixed with the resin, and six grams of diethylene triarnine wasthen added. The heat caused decomposition of the ammonium carbonate[(NH4)2CO3], the blowing agent, into water, ammonia (NH3) and carbondioxide. The release of the carbon dioxide caused the resin to foam.Experience has shown that the foam so produced is characterized by aninterconnecting cellular structure, with the size of the cells beingcontrolled primarily by the amount of wetting agent used. Curing of theresin is controlled by the hardener used (in this case, diethylenetriamine). Another blowing agent besides ammonium carbonate which may beused, is diazo amino benzene.

Second-To obtain a phenolic foam the materials used were: about 90percent of A-stage phenolic resin (liquid and soluble); about 0.2percent of sorbitan monolaurate polyoxyalkylene derivative, a wettingagent; about 0.7 percent of sodium b-icarbonate (the blowing agent andcatalyst); and about 9 percent of a 40 percent solution ofphenolsulfonic acid. The acid was added to the other ingredients andagitated vigorously for l to` 20 seconds. Without the necessity for anyprovision of heat, a foam having a density of one-third to 20 pounds percubic foot (depending upon the volume in which the foam was contained)with good heat resistance and with an interconnecting cellular structurewas obtained. It was found possible to substitute ammonium carbonate forthe sodium carbonate with equally good results.

In view of the foregoing, it will be seen that this invention provides anovel bearing structure which readily lends itself to economical methodsof providing such structure.

While the invention has been explained by a particular embodimentthereof, it will be apparent that improvements and modifications may bemade without departing from the scope of the invention as defined in theappended claims.

What l claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. in combination: a sleeve bearing; a shaft rotatably journalcd in saidbearing and extending axially beyond at least one end thereof, saidbearing having an opening formed therein communicating with the journalsurface of said shaft; a bearing 4housing including a portion extendingradially outwardly from the other end of said .bearing and securedthereto for supporting the same, said bearing housing including agenerally cup-shaped member arrangedconcentrically about said bearingand shaft with its open end secured to said radially extending bearinghousing portion and'having an opening formed in its bottom with saidshaft extending therethrough with a running clearance, saidradiallysextending bearing 4housing portion and said cup-shaped memberdefining a first cavity with said bearing and lsaid shaft, said bottomof said cup-shaped lmember being spaced axially from said one end ofsaid bearing and forming `an annular opening communicating with saidfirst cavity, said first cavity having at least'one cross-sectional areaparallel to and substantially greater than the cross-section of saidannular opening; said bearing housing having an axiallyv extendingportion projecting outwardly from the other side of said radiallyextending portion surrounding said shaft and forming a second cavitywith said radially extending portion and said shaft; an integral mass oflubricant-absorbent foam material having an interconnecting cellularstructure filling said bearing opening and said first and secondcavities, said material being spaced from said shaft in each of saidcavities; and means disposed on said shaft in at least one of saidcavities adjacent one end of said bearing for centrifugally throwinglubricant into said lubricant-absorbent material.

2. In combination: a sleeve bearing; a shaft rotatably journaled intosaid bearing and extending axially beyond each end thereof, said bearinghaving an opening formed therein communicating with the journal surfaceof said shaft; a bearing housing having a first portion extendingradially outwardly from one end of said bearing `and secured thereto forsupporting the same, said bearing housing having a second portionextending axially outwardly from one side of said first portionsurrounding said bearing and said shaft and having an opening formedtherein with said shaft extending therethrough with a running clearance,said first and second housing portions defining a first generallyannular cavity with said bearing and said shaft, and second housingportion extending axially beyond the other end of said bearing formingan annular opening communicating with said first cavity, said firstcavity having yat least one cross-sectional area parallel to andSubstantially greater than the cross-section of said annular opening,said housing having a third portion extending axially outwardly frornthe other side of said first portion surrounding said shaft and forminga second cavity with said first housing portion and said shaft; anannular member closing said second cavity and having an opening formedtherein with said shaft extending therethrough with a running clearance;said first housing portion having a plurality of axially extendingopenings formed therein around said bearing defining spokes andcommunicating with said first and second cavities; an integral mass oflubricant-absorbent foam material having an interconnecting cellularstruct re filling said bearing opening and said first cavity, extendingthrough said yaxial openings in said first housing portion, and formingan annular layer in said second cavity spaced from said shaft; and alubricant slinging member on said shaft in said second cavity forcentrifugally throwing lubricant into said annular layer of lubricantabsorbent material.

References Cited in the file of this patent UNlTED STATES PATENTS2,078,783 Welch Apr. 27, 1937 2,138,971 Keeler et al Dec. 6, 19382,289,624 Brown et al. July 14, 1942 2,448,154 Richmond Aug. 3l, 19482,572,568 Gluesenkamp Oct. 23, 1951 2,739,020 Howes Mar. 20, 19562,739,134 Parry et al. Mar. 20, 1956 2,751,265 Wightman lune 19, 19562,753,642 Sullivan July 10, 1956 FOREIGN PATENTS 401,596 Great BritainNov. 16, 1933 938,941 France Dec. 15, 1954

